Vehicle charging circuit and vehicle electrical system having the vehicle charging circuit

1. A vehicle charging circuit, comprising:

an AC voltage connection that has a plurality of potentials;

a switch device;

a plurality of rectifiers that are each in the form of a bridge rectifier;

a plurality of step-up converters; and

a plurality of galvanically isolating DC-DC converters,

wherein inputs of the rectifiers are connected to one another and the interconnected inputs of the rectifiers are connected to the AC voltage connection via the switch device, and

the rectifiers each have an output, downstream of each of which is connected one of the step-up converters, and the step-up converters are connected to a rechargeable battery connection of the vehicle charging circuit.

2. The vehicle charging circuit as claimed in claim 1 , wherein the individual rectifiers are connected to the individual DC-DC converters via the individual step-up converters, wherein the DC-DC converters have outputs that are connected to one another and that are connected to an on-board electrical system connection.

3. The vehicle charging circuit as claimed in claim 1 , wherein the step-up converters each have a diode, a load inductor, a DC link capacitor and a converter switch, wherein in each case the diode is connected to a first DC voltage potential of the connected rectifier via the load inductor and is connected to a second DC voltage potential of the connected rectifier via the converter switch, and the DC link capacitor is connected to the second DC voltage potential hand to that end of the diode that is opposite the converter switch.

4. The vehicle charging circuit as claimed in claim 1 , which is equipped with two rectifiers and two DC-DC converters, wherein the DC-DC converters each have a first input potential and a second input potential, and the rechargeable battery connection is connected to the first input potential of the first DC-DC converter and to the second input potential of the second DC-DC converter.

5. The vehicle charging circuit as claimed in claim 1 , wherein the AC voltage connection is configured to be connected to the outer conductors of a single-phase three-wire power supply network.

6. The vehicle charging circuit as claimed in claim 1 , wherein the AC voltage connection is provided in the form of a plug-in connection element that is designed in accordance with the ANSI/NEMA WD 6-2002 standard, in particular in the form of a socket or plug connector in accordance with NEMA 6-15, NEMA L6-15, NEMA 6-20, NEMA L6-30, NEMA 6-30, NEMA 6-50, NEMA L6-50, NEMA 10-30 or NEMA 10-50.

7. The vehicle charging circuit as claimed in claim 1 , which also has a DC voltage connection, wherein the rechargeable battery connection is connected to the DC voltage connection via rechargeable battery isolating switches of the vehicle charging circuit.

8. The vehicle charging circuit as claimed in claim 7 , which also has connecting switches that connect the DC voltage connection to different potentials of the outputs of the different rectifiers in a switchable manner.

9. The vehicle charging circuit as claimed in claim 1 , wherein the inputs of the rectifiers are connected to one another directly or are connected to one another in a switchable manner via an additional switch device.

10. A vehicle electrical system comprising a vehicle charging circuit as claimed in claim 1 , a rechargeable battery and an on-board electrical system branch, wherein the rechargeable battery is connected to the rechargeable battery connection of the vehicle charging circuit and the on-board electrical system branch is connected to the on-board electrical system connection of the vehicle charging circuit.

11. The vehicle charging circuit as claimed in claim 2 , wherein the step-up converters each have a diode, a load inductor, a DC link capacitor and a converter switch, wherein in each case the diode is connected to a first DC voltage potential of the connected rectifier via the load inductor and is connected to a second DC voltage potential of the connected rectifier via the converter switch, and the DC link capacitor is connected to the second DC voltage potential and to that end of the diode that is opposite the converter switch.